Use After Free Affecting ocfs2-kmp-default package, versions <6.4.0-150700.53.73.2


Severity

Recommended
0.0
medium
0
10

Based on SUSE Linux Enterprise Server security rating.

Threat Intelligence

EPSS
0.13% (3rd percentile)

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  • Snyk IDSNYK-SLES157-OCFS2KMPDEFAULT-18210921
  • published22 Jul 2026
  • disclosed21 Jul 2026

Introduced: 21 Jul 2026

NewCVE-2026-53161  (opens in a new tab)
CWE-416  (opens in a new tab)

How to fix?

Upgrade SLES:15.7 ocfs2-kmp-default to version 6.4.0-150700.53.73.2 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream ocfs2-kmp-default package and not the ocfs2-kmp-default package as distributed by SLES. See How to fix? for SLES:15.7 relevant fixed versions and status.

In the Linux kernel, the following vulnerability has been resolved:

misc: fastrpc: fix use-after-free of fastrpc_user in workqueue context

There is a race between fastrpc_device_release() and the workqueue that processes DSP responses. When the user closes the file descriptor, fastrpc_device_release() frees the fastrpc_user structure. Concurrently, an in-flight DSP invocation can complete and fastrpc_rpmsg_callback() schedules context cleanup via schedule_work(&ctx->put_work). If the workqueue runs fastrpc_context_free() in parallel with or after fastrpc_device_release() has freed the user structure, it dereferences the freed fastrpc_user. Depending on the state of the context at the time of the race, any one of the following accesses can be hit:

  1. fastrpc_buf_free() calls fastrpc_ipa_to_dma_addr(buf->fl->cctx, ...) to strip the SID bits from the stored IOVA before passing the physical address to dma_free_coherent().

  2. fastrpc_free_map() reads map->fl->cctx->vmperms[0].vmid to reconstruct the source permission bitmask needed for the qcom_scm_assign_mem() call that returns memory from the DSP VM back to HLOS.

  3. fastrpc_free_map() acquires map->fl->lock to safely remove the map node from the fl->maps list.

The resulting use-after-free manifests as:

pc : fastrpc_buf_free+0x38/0x80 [fastrpc] lr : fastrpc_context_free+0xa8/0x1b0 [fastrpc] fastrpc_context_free+0xa8/0x1b0 [fastrpc] fastrpc_context_put_wq+0x78/0xa0 [fastrpc] process_one_work+0x180/0x450 worker_thread+0x26c/0x388

Add kref-based reference counting to fastrpc_user. Have each invoke context take a reference on the user at allocation time and release it when the context is freed. Release the initial reference in fastrpc_device_release() at file close. Move the teardown of the user structure — freeing pending contexts, maps, mmaps, and the channel context reference — into the kref release callback fastrpc_user_free(), so that it runs only when the last reference is dropped, regardless of whether that happens at device close or after the final in-flight context completes.

CVSS Base Scores

version 3.1